Download Routes of Drug Administration

Routes of Drug Administration
Tissue Engineering & Drug Delivery
BBI 4203
LECTURE #11
Classifications for route of
administration
• Path by which a drug, fluid, poison, or other substance
is taken into the body.
• Generally classified by the location at which the
substance is applied.
– Common examples include oral and intravenous
administration.
• Also can be classified based on where the target of
action is.
– topical (local)
– enteral (system-wide effect, but delivered through the
gastrointestinal tract)
– parenteral (systemic action, but delivered by routes other
than the GI tract)
Gastrointestinal/enteral
• Administration through the gastrointestinal
tract
• Enteral -- literally meaning 'through the
intestines’
• Includes oral and rectal administration
Pills
Suppositories
Epicutaneous or topical
• Application of creams or salves onto the skin
• Drug diffuses through skin in a transdermal
route
Intravenous administration
• Administration into a
vein
• Most common drug,
fluids and nutrition
infusion route
Central nervous system
• Epidural: injection or infusion into
the epidural space.
– relieve pain during child birth
• Intracerebral: direct injection into
the brain.
– can also interrupt the blood brain
barrier from holding up against
subsequent routes
• Intracerebroventricular: injection
or infusion the ventricular system
of the brain.
– pain meds for terminal cancer
patients with intractable pain
Nasal administration
• Can act topically through the nasal epithelium
• Or taken up through the respiratory tract as
an inhalant
Intra-arterial administration
• Administration into
an artery
• vasodilator drugs in
the treatment of
vasospasm
• thrombolytic drugs
for treatment of
embolism
Intra-articular administration
• Administration into a joint space.
• Used in treating osteoarthritis
• Corticosteroids or hylauronic acid
Intracardiac administration
• Administration into the heart (emergencies)
• Injection of adrenaline during
cardiopulmonary resuscitation
Direct injection
Adrenalin injection scene from
the movie Pulp Fiction
John Travolta, Samuel L. Jackson, Uma Thurman
https://www.youtube.com/watch?v=jpMxpzfSRUA
Intramuscular administration
• Administration into a muscle
• Many vaccines, antibiotics, and long-term
psychoactive agents.
Intraocular administration
• Medications for glaucoma or eye neoplasms
Intraosseous infusion
• Administration into the bone marrow that
drains directly into the venous system.
• Occasionally used in emergency medicine and
pediatrics when intravenous access is difficult.
Intraperitoneal administration
• Infusion or injection into the peritoneum
• Peritoneal dialysis
Intrathecal administration
• Administration directly into the spinal cord
• Most commonly used for spinal anesthesia,
pain relief, and chemotherapy
Epidural
Intrathecal
Subcutaneous administration
• Administration under the skin
• Vaccines, insulin, morphine, injection
• Commonly used in with recreational drugs
Transdermal administration
• Diffusion of drug through the intact skin
• Transdermal patches such as fentanyl in pain
therapy, nicotine patches for treatment of
addiction and nitroglycerine for treatment of
angina pectoris, hormone therapy.
Transmucosal administration
• Drug diffusion through a mucous membrane
• Insufflation (through nasal membranes),
sublingual (under the tongue), sublabial
(between the lips) and gingiva (between cheek
and gum), nitroglycerine, vaginal suppositories
Snorting drugs
Nitroglycerin pill for relief of angina
Controlled release
• Most commonly it refers to time dependent release
in oral dose formulations such as prolonged release,
pulse release, delayed release.
• Attempts to maintain drug levels within the
therapeutic window to avoid potentially hazardous
peaks in drug concentration following ingestion or
injection.
Targeted drug delivery
• Delivering medication in a manner that prolongs
the concentration drug in diseased tissues and
minimizes concentration in non-diseased tissues.
• Reduces total drug dose and frequency of
administration.
• 3 main mechanisms
– physically locate the drug depot at the diseased site
– use molecular recognition to bind circulating drug to
diseased tissue
– mechanism that bursts open circulating drug carriers
at site of diseased tissue
“Homing” liposomes and drug eluting
stents
Infusion pumps
• Pump-controlled infusion of drug
• Large volume pumps can pump nutrient
solutions large enough to feed a patient.
• Small-volume pumps infuse hormones, such
as insulin, or other medicines, such as opiates.
All drugs move through three tissue
compartments
Blood and lymph vessels (1 - 10%)
Interstitial space
Cells
Different fractions, types and orientation of
cells, ECM, interstitial space, vasculature in
different tissues